More particularly, the invention relates to a wave-propagation probing method, said method comprising:                (a) a transmission step during which a transducer array (that is to say all or some of the transducers of the array) transmits an incident wave into a medium that scatters said wave;        (b) a measurement step during which said transducer array (that is to say all or some of the transducers of the array) captures signals representative of a reflected wave reverberated by the medium on the basis of the incident wave, said captured signals comprising:                    a single scattering component representative of wave paths in which the reflected wave results from a single reflection of the incident wave by scatterers belonging to the medium, and            as the case may be, a multiple scattering component representative of wave paths in which the reflected wave results from several successive reflections of the incident wave by the scatterers in the medium before reaching the transducer array; and                        (c) a processing step during which said captured signals are processed so as to determine characteristics of the medium (the characteristics in question may consist of an image of the medium and/or a value of a parameter of the medium and/or the presence or absence of a singular point, such as a heterogeneity, etc.).        
The abovementioned processing step makes it possible, for example, to measure a characteristic parameter of the medium and/or to detect a singular point in the medium and/or to produce an image of the medium.
Methods of this type are used especially in detection and imaging systems such as, for example, sonars, radars, echographs, etc.
In the known methods of this type and especially in echographic or radar imaging methods, the single scattering component of the captured signals is used: if each scatterer interacts only once with the wave, there is in fact a direct equivalence between the arrival time of each echo and the distance separating the transducer from the scatterer that has generated this echo. The detection of an echo at a given instant indicates the presence of a scatterer at the distance corresponding to the echo arrival time. An image of the reflectivity of the medium, that is to say an image of the position of the various scatterers within the medium, may, as the case may be, then be constructed from the captured signals.
In contrast, multiple scattering is not used in echographic or radar imaging methods. Quite on the contrary, these imaging methods are based on the assumption that said multiple scattering is negligible. However, in the presence of a substantial multiple scattering component, especially when the scatterers contained in the medium have a high scattering power and/or are very dense within the medium, the conventional imaging methods are highly disturbed and no longer reliable. This is because, in such a case, there is no longer equivalence between the arrival time of an echo and the distance separating a transducer from a scatterer in the medium, thereby preventing an image of the medium from being constructed.